I wanted to discuss a few things about the Dark Eldar within the void of not being on the tabletop. This is because when list building it is important to have a cohesive strategy on what is going to do what when you hit the table top. Part of that learning curve of the Dark Eldar is learning the specifics of their weapons. The picture was me doing inventory a few months back to see what I had, and what I needed to get.
While each player looks at things differently, I am presenting this only as the way I see them. If you look at them differently, that is great. This is what works for me, and how I think of each weapons role on the battlefield. Here are the two things I am talking about.
1. Dark Light Weaponry
2. Splinter Weapons
Darklight Weaponry:
Over-all this is an early game weapon. While there will be uses for it in late game, your goal should always be to break armour early. We have all had instances where we have had to use that heavy tank killing weapon on infantry due to lack of targets. Normally there is still something around to shoot at, but later in the game your targets start to thin out.
This means that during list building, it is important to find just the right amount of armour breaking weaponry. Stationary Dark Lances in a Dark Eldar list should be limited, with more of your armour breaking guns going to blasters. You have something very special with 18" armour breaking assault weapons, so capitalize on it. Starting off in a Raider, moving 12", Rotate 3" jumping off 3", and firing 18" with a Blaster should make you tremble with excitement. That is 36", and is mobile for following rounds. Notice the 36" initial range vs a Dark Lance 36" range. If something has a Stationary Dark Lance, it should be for a reason other than armour breaking, examples being; backfield objective holding units, or super cheap two lance wielding trueborn.
Do not be afraid of midfield. In fact you are dark eldar. Take it. Maybe not right in front of the incoming horde, but do not fear the midfield, take it. It might be on the right or left flank, but the midfield is where your units should be, and quickly.
How about this. Next round if you need to move sideways across the board and your raider is still alive. You are already in range to board, so get on movement up 6", move raider 6" rotate again 3" and fire from any point on the raider 18". Now you will never get this full movement (I haven't), but reboarding a raider (doesn't even have to be the one you were on) for extra distance gives you a maximum of 33" range the following round. Too many factors to get maximum range here, but you get the idea that jumping into your raider along with the vehicle 6" move and rotate will give you that extra mile to reach things that you could not before.
Splinter Weaponry:
We are blessed with a codex that gives us great darklight guns, and lots of splinter weaponry. In fact a list that simply concentrates on Darklight and Splinter Weaponry is a great combination list by itself. Lets look at the guns.
Mid and Late game should be about killing infantry, or other things not as often in the armour protection. This makes splinter weapons extremely valuable weapons after that first round when infantry are exposed. First round you have to concentrate on taking down a few transports and armour for your splinter weapons to do their magic.
The great thing about splinter weapons vs marines is who cares whether or not they are in cover. See one shoulder pad, unleash hell into them. Mow them down. Only vs light Sv5+ infantry do we even care if our opponents are in cover with splinter weapons. In fact it seems to take the advantage away from them, so make sure you point this out to your opponent. (with a smile of course).
Splinter Cannons. I love these weapons. These are a Heavy 6 or Assault 4 with a 36" range. Great range with flexibility to move or stand still. Get these into a midfield position and they command the battlefield, mowing down monstrous creatures, infantry etc. How many do you need? Well I prefer a shot count that is rather high for long range splinter weapons. I do not count my rifles. I need at least double the shot capacity of my blaster/lances.
Venoms; this is a great place to get splinter cannons. I mean cheap. The issue is, remember that your transports if low in total count, will go down quickly. If you are only fielding a couple transports 1-5, consider not taking venoms. You need your splinter cannons to last, and not blow up too quickly. I would rather lose a Raider than a Venom. 7 is my magic number. If I have 7 transports, 2 will be venoms. Raiders have the ability to blow up armour early game, and that is what dark eldar need. I have seen all venoms lists. These would probably be the exception to my magic number of 7.
I am not going to go into detail Cannons vs Carbines or Pods. You should be going with any of them, but the point is you should be going with them. Pick your flavor, and go. While I do not count rifles in my shooting counts, they do make a difference in game, so do not forget them.
The Point:
Blasters and lances are great weapons, take a lot of them. however as the rounds progress you will need less of them, and more ways to kill infantry. This is where splinter weapons come into play. The great counterbalance to your list is laying down huge torrents of long range splinter weapon fire along side blasters and lances. Its a great combination on the field, and if you can combine that with assault elements, well, you have a list.